Pollution atmosphérique et poumon : approche épidémiologique

Abstract

L’appareil respiratoire constitue une voie d’exposition privilégiée pour les aérocontaminants, qu’il s’agisse de gaz ou de particules qui peuvent avoir des effets nocifs à court ou long terme. En moyenne, l’homme respire 15 m3 d’air par jour et, en milieu urbain, passe plus de 80 % de son temps à l’intérieur des locaux. La diversité des méthodes épidémiologiques utilisées par plusieurs équipes dans des lieux différents et la cohérence générale de ces observations montrent que les effets à court ou long terme de l’exposition aux polluants de l’intérieur et de l’extérieur des locaux, bien que faibles, restent décelables.

Epidemiological evidence has concurred with clinical and experimental evidence to correlate current levels of ambient air pollution, both indoors and outdoors, with respiratory effects. In this respect, the use of specific epidemiological methods has been crucial. Common outdoor pollutants are particulate matter, nitrogen dioxide, carbon monoxide, volatile organic compounds and ozone. Short-term effects of outdoor air pollution include changes in lung function, respiratory symptoms and mortality due to respiratory causes. Increase in the use of health care resources has also been associated with short-term effects of air pollution. Long-term effects of cumulated exposure to urban air pollution include lung growth impairment, chronic obstructive pulmonary disease (COPD), lung cancer, and probably the development of asthma and allergies. Lung cancer and COPD have been related to a shorter life expectancy. Common indoor pollutants are environmental tobacco smoke, particulate matter, nitrogen dioxide, carbon monoxide, volatile organic compounds and biological allergens. Concentrations of these pollutants can be many times higher indoors than outdoors. Indoor air pollution may increase the risk of irritation phenomena, allergic sensitisation, acute and chronic respiratory disorders and lung function impairment. Recent conservative estimates have shown that 1.5–2 million deaths per year worldwide could be attributed to indoor air pollution. Further epidemiological research is necessary to better evaluate the respiratory health effects of air pollution and to implement protective programmes for public health.